The CAS Authentication plugin allows for StatusNet to handle authentication
through CAS (Central Authentication Service).

Installation
============
add "addPlugin('casAuthentication',
    array('setting'=>'value', 'setting2'=>'value2', ...);"
to the bottom of your config.php

Settings
========
provider_name*: a unique name for this authentication provider.
authoritative (false): Set to true if CAS's responses are authoritative
    (if authorative and CAS fails, no other password checking will be done).
autoregistration (false): Set to true if users should be automatically created
    when they attempt to login.
email_changeable (true): Are users allowed to change their email address?
    (true or false)
password_changeable*: must be set to false. This plugin does not support changing passwords.

server*: CAS server to authentication against
port (443): Port the CAS server listens on. Almost always 443
path (): Path on the server to CAS. Usually blank.
takeOverLogin (false): Take over the main login action. If takeOverLogin is
    set, anytime the standard username/password login form would be shown,
    a CAS login will be done instead.

* required
default values are in (parenthesis)

Example
=======
addPlugin('casAuthentication', array(
    'provider_name'=>'Example',
    'authoritative'=>true,
    'autoregistration'=>true,
    'server'=>'sso-cas.univ-rennes1.fr',
    'port'=>443,
    'path'=>'',
    'takeOverLogin'=>true
));

